Abstract: Objective To investigate the relationship between the pathophysiological changes and memory function in patients with obstructive sleep apnea/ hypopnea syndrome(OSAHS).Methods Twenty-one patients with OSAHS were monitored for sleep efficiency, apnea/hyponea index, minimal oxygen saturation(SaO₂) during sleep, average oxygen saturation during sleep and total sleep time of SaO₂<90% by polysomnography tests. Their memory functions were measured by neuropsychological tests. The Epworth sleepiness scale was used to assess the degree of patients' daytime somnolence.Results Memory function of patients with OSAHS was significantly associated with total sleep time of SaO₂<90%(standardized coefficients=-0.643, P<0.01); but memory function of patients with OSAHS was not associated with sleep efficiency, apnea/hypopnea index(AHI), average oxygen saturation(SaO₂) during sleep, minimal SaO₂ during sleep and excessive daytime somnolence(EDS).Conclusion Memory function in patient with OSAHS correlates with hypoxia. AHI and SaO₂ are not sensitive for assessment of the memory dysfunction in those patients.

Key words: obstructive sleep apnea/hypopnea syndrome(OSAHS), memory, cognitive function